Alaska Section, AWRA, Northern-Region Brown-Bag Meetings

January 26, 2018

Tundra Be Dammed: Beaver Colonization of the Arctic

Dr. Ken Tape, Research Assistant Professor,
Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, Alaska
Phone: (907) 474-2775, Email:

Increasing air temperatures are changing the arctic tundra biome. Permafrost is thawing, snow duration is decreasing, shrub vegetation is proliferating, and boreal wildlife is encroaching. Here we present evidence of the recent range expansion of North American beaver (Castor canadensis) into the Arctic, and consider how this ecosystem engineer might reshape the landscape, biodiversity, and ecosystem processes. We developed a remote sensing approach that maps formation and disappearance of ponds associated with beaver activity. Since 1999, 56 new beaver pond complexes were identified, while only 4 beaver ponds exhibited drying, indicating that beavers are colonizing a predominantly tundra region (18,293 km2) of northwest Alaska. We discuss rates and likely routes of tundra beaver colonization, as well as effects on permafrost, stream ice regimes, and freshwater and riparian habitat. Beaver ponds and associated hydrologic changes are thawing permafrost. Pond formation increases winter water temperatures in the pond and downstream, likely creating new and more varied aquatic habitat, but specific biological impacts are unknown. Beavers create dynamic wetlands and are agents of disturbance that may enhance ecosystem responses to warming in the Arctic.

Select Presentation Figures

Figure A. Tundra landscape in the western Brooks Range. When do YOU think beavers arrived?, High Resolution Image

Webex Registration Available

  • Registration Link
  • Event number: 664 676 939
  • Event password: ArcticBeavers
  • Registration Notes: Webex will be started at 11:45 am, if you have not joined a Webex before from your computer, please join early to verify your connection
  • Meeting and Presentation Duration: We will start the Webex at 11:45, on-site attendees start to arrive about the same time, we will start the presentation by 12:10 or ealier, presentations end around 1:00 pm, followed by questions. We will not go past 1:30 pm with questions.
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Some Additional References of Interest by Dr. Ken Tape